The current operational methods of launching decoys from US Navy ships are the RBOC and SRBOC countermeasure launchers. Both use a chemical propellant to accelerate a round to the desired velocity. They are fixed in azimuth and elevation and the velocity is determined by the amount of propellant and weight of the round. As such, they are limited in their effectiveness because they cannot be deployed at the best distance and angle to counter an approaching threat. The rounds used in the launcher cannot be tailored for the platform from which it is launched.
The current operational method of launching decoys from US Navy aircraft is the ALE-40 countermeasure dispenser. This dispenser usually ejects decoys from the bottom of the aircraft straight down. The decoys are launched with no forward velocity component and separate from the aircraft quickly. Advanced threats can use these characteristics to discriminate the decoy from the target and reject the decoy.
A launching system heretofor employed and designed solely for launching munition-type projectiles is an electromagnetic rail gun. In electromagnetically-driven rail guns, two metallic rails in the gun barrel (bore) serve as electrodes that conduct current to a conducting armature wedged tightly between the rails. The armature is placed at the back of the projectile that delivers a payload. A fast, high-current pulse loops through the rails via the armature, generating a magnetic field that couples with the current passing through the armature to produce a force that accelerates the projectile down the barrel at supersonic speeds.
Exemplary rail gun designs are described in U.S. Pat. No. 7,409,900. Nechitailo et al. issued Aug. 12, 2008; U.S. Pat. No. 7,077,047, J. F. Frasca, issued Jul. 18, 2006; U.S. Patent Application No. 20080053299. R. J. Taylor, publication date Mar. 6, 2008; and U.S. Patent Application No. 20070277668, J. F. Frasca, publication date Dec. 6, 2007; all of which are incorporated herein by reference. These rail gun designs, however, are not focused on the specific issue of how best to launch an electronic countermeasure such as a decoy. For example, as discussed above, the projectile in prior systems is accelerated down the barrel at supersonic speeds.
The speeds required for decoy launching are variable but typically a fraction of those required for munition-type projectiles. The chemical propellant used in these systems also has the known safety concerns of handling the charge along with the safety and logistical (e.g. supply chain) issues involved in storing and replacing the charges.
It would therefore be advantageous to provide an electromagnetic rail gun system for safely launching a decoy at user-selected launch velocities and angles.